be a law to oneself

• 我行我素

be a law to oneself的用法和样例：

例句

1. Boys of that age are a law unto themselves.
   这个年龄的男孩子们都是我行我素的。
2. The boy has a will of his own in doing everything.
   这孩子做任何事都是我行我素。
3. Now they must eat the fruit of their own way, and with their own devices be glutted.
   所以他们必要自食其果，饱尝独断独行的滋味。